feat(11-02): add Sites to sidebar navigation and tenant index page

- MapPin icon and Sites nav link in sidebar Fleet section
- Tenant index shows Sites count card in 3-column grid
- "Manage sites" link added to tenant index bottom links

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/layout/Sidebar.tsx

@@ -14,6 +14,7 @@ import {
   ClipboardList,
   Wifi,
   BarChart3,
+  MapPin,
 } from 'lucide-react'
 import { cn } from '@/lib/utils'
 import { useAuth, isSuperAdmin, isTenantAdmin } from '@/lib/auth'
@@ -110,6 +111,15 @@ export function Sidebar() {
               },
             ]
           : []),
+        ...(!isSuperAdmin(user) && user?.tenant_id
+          ? [
+              {
+                label: 'Sites',
+                href: `/tenants/${user.tenant_id}/sites`,
+                icon: MapPin,
+              },
+            ]
+          : []),
         {
           label: 'Wireless',
           href: '/wireless',

frontend/src/routes/_authenticated/tenants/$tenantId/index.tsx

@@ -1,7 +1,7 @@
 import { createFileRoute, Link } from '@tanstack/react-router'
 import { useQuery } from '@tanstack/react-query'
-import { Users, Monitor, Building2 } from 'lucide-react'
+import { Users, Monitor, Building2, MapPin } from 'lucide-react'
-import { tenantsApi } from '@/lib/api'
+import { tenantsApi, sitesApi } from '@/lib/api'
 import { formatDate } from '@/lib/utils'
 import { CardGridSkeleton } from '@/components/ui/page-skeleton'
 
@@ -17,8 +17,13 @@ function TenantDetailPage() {
     queryFn: () => tenantsApi.get(tenantId),
   })
 
+  const { data: sitesData } = useQuery({
+    queryKey: ['sites', tenantId],
+    queryFn: () => sitesApi.list(tenantId),
+  })
+
   if (isLoading) {
-    return <CardGridSkeleton cards={2} />
+    return <CardGridSkeleton cards={3} />
   }
 
   if (!tenant) {
@@ -40,7 +45,7 @@ function TenantDetailPage() {
         </div>
       </div>
 
-      <div className="grid grid-cols-2 gap-4">
+      <div className="grid grid-cols-3 gap-4">
         <Link
           to="/tenants/$tenantId/users"
           params={{ tenantId }}
@@ -53,6 +58,18 @@ function TenantDetailPage() {
           </div>
         </Link>
 
+        <Link
+          to="/tenants/$tenantId/sites"
+          params={{ tenantId }}
+          className="flex items-center gap-3 rounded-lg border border-border bg-surface p-4 hover:bg-elevated/50 transition-colors group"
+        >
+          <MapPin className="h-8 w-8 text-text-muted group-hover:text-text-muted transition-colors" />
+          <div>
+            <p className="text-2xl font-semibold">{sitesData?.sites.length ?? 0}</p>
+            <p className="text-xs text-text-secondary">Sites</p>
+          </div>
+        </Link>
+
         <Link
           to="/tenants/$tenantId/devices"
           params={{ tenantId }}
@@ -75,6 +92,14 @@ function TenantDetailPage() {
           Manage users
         </Link>
         <span className="text-text-muted">·</span>
+        <Link
+          to="/tenants/$tenantId/sites"
+          params={{ tenantId }}
+          className="text-sm text-text-secondary hover:text-text-primary transition-colors underline-offset-2 hover:underline"
+        >
+          Manage sites
+        </Link>
+        <span className="text-text-muted">·</span>
         <Link
           to="/tenants/$tenantId/devices"
           params={{ tenantId }}